Foundation excavation is a process within the construction industry to prepare the foundation for construction. The foundation excavation procedure involves site clearance, setting out, excavation and concrete pouring.
Keep reading to learn more about foundation excavation and the steps involved in the process.
What Is Foundation Excavation?
Foundation excavation is the process of digging into the soil where the foundation is to be laid. The hole must ensure adequate depth and width to enable the foundation to be located below the level of ground freezing and guarantee the structure will be stable.
The type of excavation and depth of the hole depend on the ground, the structure load and the planned foundation. Foundation excavation requires specialised construction machinery and protection of the excavation walls against loose soil.
The Excavation Process
Site Clearance
Before the excavation process can begin, the site must be cleared. Any vegetation like underbrush within the perimeter of the site must be removed. If any surrounding trees could interfere with the building work, these should also be removed. Roots must be cut back to at least a foot below where the foundation will lay.
If the site has previously had another structure, you may need the assistance of demolition contractors to demolish and remove the building to prepare the foundation for excavation. If removing items is likely to cause issues for the excavation or laying of the foundation, they can be filled and compacted instead.
Setting Out The Foundation Layer
The site is set out by using wooden pegs and strings to mark out the excavation perimeter. The depth of the foundation must be determined by a general contractor before commencing the excavation.
Excavation Procedure
Depending on the scale of the excavation, pick axes, crowbars and spades may suffice. For larger buildings and deep foundation excavation, heavy machinery like excavators are required to dig and remove the soil.
For hard soils, when the excavation is less than 1.5m, the trench walls don’t require extra support. However, if the soil is loose or particularly deep, the trench walls may need to be reinforced with wooden planks while the excavation takes place.
De-watering of Excavation
If the foundation poses the threat of waterlogging, it's necessary to de-water the excavation area. A site and soil investigation may be conducted to determine the best method to de-water the area.
Concreting of Foundation in Excavation
Once the area has been excavated, the foundation can be poured. The concrete mix will be poured into the trench and covered with moist gunny bags for 1 to 2 hours after being laid. The curing of the foundation lasts between 3 to 10 days. Masonry work can begin after 3 days, but the curing process should be continued alongside it.
Foundation excavation can be a time-consuming part of the construction process. If you’re looking for a reliable and experienced company to handle the foundation excavation of your site, look no further than P R Weldhen.
For more information about our demolition or excavation services or excavator hire contact us today.
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